Abstract:
A rotational speed control system, comprising a plurality of motor drivers for driving a plurality of motors at a same rotational speed without relying upon the quantity of the motor drivers and the characteristics of the motor drivers, wherein a remote controller (31) and the motor driver (202) are connected to the motor driver (201), the motor drivers (201, 202) control the motors (M11, M12) at specified rotational speeds, and a rotational speed instructing signal (91) indicating the rotational speeds is given from the remote controller (31) to the motor driver (201) and then given from the motor driver (201) to the motor driver (202), whereby since the rotational speed instructing signal (91) instructs the rotational speeds digitally exchanged between the motor drivers (201, 202), both motors (M11, M12) can be driven at the rotational speeds instructed by the rotational speed instructing signal (91).
Abstract:
Noise countermeasures are efficiently taken for a semiconductor circuit board and a semiconductor circuit. The semiconductor circuit board is provided with a control board (1) and a semiconductor circuit (2) connected to the control board (1). The semiconductor circuit (2) is provided with a board (21), an integrated circuit group (22) and noise countermeasure means (23, 231), and is separated from the control board (1). The integrated circuit group (22) includes an integrated circuit to be a noise generating source. The board (21) is a multilayer board and shifts the frequency of noise generated from the integrated circuit group (221) to high frequency. The noise countermeasure means (23) is a filter connected between the integrated circuit group (22) and the control board (1) and attenuates high frequency of noise.
Abstract:
From the flash memory of an existing multi−air conditioner, identification information containing the information on the machine type for applying a control program, an objective flash memory and a version is read in. A control program stored in the flash memory is compared with a control program incorporated in a portable personal computer of a service man and a decision is made that the incorporated control program is an appropriate control program before rewriting the control program.